<PAGE>

                     U.S. SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                   FORM 10-QSB

(Mark One)
 X     QUARTERLY REPORT UNDER SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT
---    OF 1934


For the quarterly period ended   March 31, 2003
                                ---------------

 _____TRANSITION REPORT UNDER SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT

For the transition period from ______________  to  ______________

                          Commission file number 04863
                                                -------

                    Southern Investors Service Company, Inc.
                    ----------------------------------------
        (Exact name of small business issuer as specified in its charter)

<TABLE>
                       Delaware                                                74-1223691
                       --------                                                ----------
<S>                                                               <C>
(State or other jurisdiction of incorporation or organization)    (I.R.S. Employer Identification No.)
</TABLE>

2727 North Loop West, Suite 200, Houston, Texas                77008
-----------------------------------------------                -----
   (Address of principal executive offices)                  (Zip Code)


                                 (713) 869-7800
                                 --------------
                            Issuer's telephone number


--------------------------------------------------------------------------------
   (Former name, former address and former fiscal year, if changed since last
                                    report)

     Check whether the issuer (1) filed all reports required to be filed by
Section 13 or 15(d) of the Exchange Act during the past 12 months (or for such
shorter period that the registrant was required to file such reports), and (2)
has been subject to such filing requirements for the past 90 days. Yes X No ____
                                                                      ---

                APPLICABLE ONLY TO ISSUERS INVOLVED IN BANKRUPTCY
                   PROCEEDINGS DURING THE PRECEDING FIVE YEARS

     Check whether the registrant filed all documents and reports required to be
filed by Section 12, 13 or 15(d) of the Exchange Act after the distribution of
securities under a plan confirmed by a court. Yes No ___ ----- -

                      APPLICABLE ONLY TO CORPORATE ISSUERS

     State the number of shares outstanding of each of the issuer's classes of
common equity, as of the latest practicable date: 3,168,929 as of May 9, 2003,
Common Stock $1.00 Par Value

     Transitional Small Business Disclosure Format (Check One): Yes ___; No X
                                                                           ---

<PAGE>

                         PART I - FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

     The Financial Statements included herein have been prepared by Southern
Investors Service Company, Inc. (the Company), without audit, pursuant to the
rules and regulations of the Securities and Exchange Commission. Certain
information and footnote disclosures normally included in financial statements
prepared in accordance with accounting principles generally accepted in the
United States of America have been condensed or omitted pursuant to such rules
and regulations, although the Company believes that the disclosures are adequate
to make the information presented not misleading. It is suggested that these
Financial Statements be read in conjunction with the Financial Statements and
notes thereto included in the Company's latest annual report on Form 10-KSB. In
the opinion of the management of the Company, all adjustments necessary to
present a fair statement of the results for the interim periods have been made.

<PAGE>

                    SOUTHERN INVESTORS SERVICE COMPANY, INC.
                                  BALANCE SHEET
                                 MARCH 31, 2003
                             (Thousands of Dollars)
                                   (Unaudited)


                                     ASSETS

Cash                                                                   $  2,190

Equity in Real Estate Joint Ventures, Net                                   286

Notes Receivable and Other Assets                                            26
                                                                       --------

       Total assets                                                    $  2,502
                                                                       ========

                      LIABILITIES AND STOCKHOLDERS' DEFICIT

Liabilities
   Notes payable, matured                                              $  4,855
   Accounts payable and accrued expenses                                  3,200
                                                                       --------

       Total liabilities                                                  8,055
                                                                       --------

Commitments and Contingencies

Stockholders' Deficit
   Preferred stock, $1 par, 1,000,000 shares authorized, none issued         --
   Common stock, $1 par, 10,000,000 shares authorized, 3,281,331
     shares issued                                                        3,281
   Additional paid-in capital                                             3,031
   Retained deficit                                                     (11,739)
   Less treasury stock, 112,402 shares, at cost                            (126)
                                                                       --------

       Total stockholders' deficit                                       (5,553)
                                                                       --------

       Total liabilities and stockholders' deficit                     $  2,502
                                                                       ========

    The accompanying notes are an integral part of this financial statement.

<PAGE>

                    SOUTHERN INVESTORS SERVICE COMPANY, INC.
                               STATEMENTS OF LOSS
           (Thousands of Dollars, Except Share and Per Share Amounts)
                                   (Unaudited)

                                                    Three Months Ended March 31,
                                                    ----------------------------
                                                        2003            2002
                                                    -----------     -----------
Revenues                                            $         7     $         6

Operating Expenses                                          (34)            (21)
                                                    -----------     -----------

Loss from Operations                                        (27)            (15)

Interest Income                                              10              12

Interest Expense                                            (78)            (77)
                                                    -----------     -----------

Net Loss                                            $       (95)    $       (80)
                                                    ===========     ===========

Basic and Diluted Loss Per Common Share             $     (0.03)    $     (0.03)
                                                    ===========     ===========

Average Number of Common Shares Outstanding           3,168,929       3,168,929
                                                    ===========     ===========

   The accompanying notes are an integral part of these financial statements.

<PAGE>

                    SOUTHERN INVESTORS SERVICE COMPANY, INC.
                            STATEMENTS OF CASH FLOWS
                             (Thousands of Dollars)
                                   (Unaudited)

                                                             Three Months Ended
                                                                  March 31,
                                                             ------------------
                                                               2003       2002
                                                             -------    -------
Cash Flows From Operating Activities:
   Net Loss                                                  $   (95)   $   (80)
   Changes in assets and liabilities:
     Decrease in notes receivable and other assets                13         16
     Increase in accounts payable and accrued expenses            78         73
                                                             -------    -------

       Net cash (used in) provided by operating activities        (4)         9
                                                             -------    -------

Cash Flows From Financing Activities:
   Payments on notes payable                                     ---        ---
                                                             -------    -------

       Net cash used in financing activities                     ---        ---
                                                             -------    -------

Net (Decrease) Increase in Cash                                   (4)         9

Beginning Cash                                                 2,194      2,242
                                                             -------    -------

Ending Cash                                                  $ 2,190    $ 2,251
                                                             =======    =======

   The accompanying notes are an integral part of these financial statements.

<PAGE>

                    SOUTHERN INVESTORS SERVICE COMPANY, INC.
                          NOTES TO FINANCIAL STATEMENTS

(1)  Current Business Conditions

     Southern Investors Service Company, Inc., (the Company), was incorporated
under the laws of the State of Delaware in 1972. Prior to 1990, the Company was
engaged in the ownership and development of real estate primarily in the
Houston, Texas area. The operations of the Company were significantly reduced
during 1990, as a result of various debt settlements with lenders and other
creditors. These settlements resulted in the transfer of substantially all of
the Company's holdings to its creditors. The Company's operations since 1990
have been limited to attempts to settle or restructure the Company's remaining
liabilities. The Company's operations also included the management of
residential developments and two office buildings owned by others. During 1998,
the majority of these residential projects were sold by the owners and therefore
the Company no longer is managing these projects. Effective January 1, 1999, the
Company ceased all management activity and all employees related to this
activity were terminated.

     The Company determined in late 1999 that the sale of Lajitas (a resort
property in west Texas), its sole remaining operating asset, would facilitate
the Company's ability to settle its existing liabilities most favorably. As a
result, the Company retained the National Auction Group, Inc., (National
Auction) to conduct an auction of Lajitas. The auction was conducted on February
24, 2000 and the property was sold for $3,950,000. The sale of the Lajitas
property closed on May 2, 2000. During 2000, the Company realized a gain on the
sale of Lajitas of $755,000 and received net cash proceeds of approximately $2.4
million, after the payment of a mortgage note related to the property sold.

     The Company has attempted to use the net proceeds from the sale of Lajitas
to settle or restructure existing debt, of which approximately $4,855,000 (plus
accrued interest) has matured and is currently past due, and to realize the
carrying amount of its remaining assets. On March 26, 2002, the Board of
Directors of the Company determined that the best alternative to settle the
Company's existing debt was to file a voluntary petition for relief under
Chapter 11 of the United States Bankruptcy Code (Chapter 11) with the United
States Bankruptcy Court (Bankruptcy Court). The Company currently anticipates
that it will file its voluntary petition with the Bankruptcy Court during 2003
and that any plan of liquidation submitted to the Bankruptcy Court in connection
therewith will call for the disposition of the Company's remaining assets and
the distribution of all the net proceeds therefrom to the Company's creditors.
These financial statements have been prepared using the historical cost basis of
accounting. Management of the Company believes the historical cost basis of
accounting states the Company's assets at

<PAGE>

approximately their liquidation values and states the Company's liabilities at
their historical amounts. It is not presently determinable what amounts the
creditors will agree to accept in settlement of the obligations due them. These
financial statements do not include any adjustments that might result from the
outcome of this uncertainty. Accordingly, the Company believes the equity of the
Company has, and will continue to have, no value and that any Chapter 11 plan
confirmed by the Bankruptcy Court will result in the elimination of the equity
interests of all of the Company's stockholders. The Company anticipates that it
will take approximately nine months after the plan is filed to complete its
liquidation process; however, any and all Chapter 11 plans that may be proposed
will be subject to obtaining all necessary approvals, including but not limited
to creditor votes and judicial determinations of confirmability. There can be no
assurance, therefore, as to how long it may take to complete the Company's
liquidation process.

(2)  Summary of Significant Accounting Policies

     The accompanying unaudited financial statements have been prepared in
accordance with the significant accounting policies included in the notes to the
Company's latest annual report on Form 10-KSB. These financial statements should
be read in conjunction with those notes.

ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OR PLAN OF OPERATION

Forward Looking Statements

     This report contains "forward looking statements" within the meaning of
Section 27A of the Securities Act of 1933, as amended, and Section 21E of the
Securities Exchange Act of 1934, as amended. All statements other than
statements of historical fact included in this section and elsewhere in this
report are forward looking statements and, although the Company believes that
the expectations reflected in such forward looking statements are reasonable, it
can give no assurance that such expectations will prove to have been correct.
The Company's business and financial results are subject to various risks and
uncertainties, including the Company's ability to settle or restructure its
remaining debt and other obligations and to generate positive cash flow to cover
its operating expenses, that may cause actual results to differ materially from
the Company's expectations. The Company does not intend to provide updated
information other than as otherwise required by applicable law. All subsequent
written and oral forward looking statements attributable to the Company or
persons acting on its behalf are expressly qualified in their entirety by the
cautionary statements contained in this paragraph and elsewhere in this report.

Current Business Conditions, Operations, Certain Events and Uncertainties

     The Company has attempted to use the net proceeds from the sale of Lajitas
to settle or restructure existing debt, of which approximately $4,855,000 (plus
accrued interest) has matured and is currently past due, and to realize the
carrying amount of its remaining assets. On March

<PAGE>

26, 2002, the Board of Directors of the Company determined that the best
alternative to settle the Company's existing debt was to file a voluntary
petition for relief under Chapter 11 with the Bankruptcy Court. The Company
currently anticipates that it will file its voluntary petition during 2003 and
that any plan of liquidation submitted to the Bankruptcy Court in connection
therewith will call for the disposition of the Company's remaining assets and
the distribution of all the net proceeds therefrom to the Company creditors. The
financial statements have been prepared using the historical cost basis of
accounting. Management of the Company believes the historical cost basis of
accounting states the Company's assets at approximately their liquidation values
and states the Company's liabilities at their historical amounts. It is not
presently determinable what amounts the creditors will agree to accept in
settlement of the obligations due them. The financial statements do not include
any adjustments that might result from the outcome of this uncertainty.
Accordingly, the Company believes that the equity of the Company has, and will
continue to have, no value and that any Chapter 11 plan confirmed by the
Bankruptcy Court will result in the elimination of the equity interests of all
of the Company's stockholders. The Company anticipates that it will take
approximately nine months after the plan is filed to complete its liquidation
process; however, any and all Chapter 11 plans that may be proposed will be
subject to obtaining all necessary approvals, including but not limited to
creditor votes and judicial determinations of confirmability. There can be no
assurance, therefore, as to how long it may take to complete the Company's
liquidation process.

Results of Operations

     The Company reported a net loss of ($95,000) or ($0.03) per share for the
quarter ended March 31, 2003 compared with a net loss of ($80,000) or ($0.03)
per share for the quarter ended March 31, 2002.

     Revenues primarily include the recognition of previously deferred gross
profits from the sale of real estate.

     Operating expenses increased due to higher legal and professional fees and
shareholder reporting expenses.

     The decrease in interest income is primarily due to the lower interest
rates during 2003.

Liquidity and Capital Resources

     As of March 31, 2003, the Company was delinquent on notes payable and other
long-term debt of approximately $4,855,000 and interest payments of $3,138,000.
As of March 31, 2003, the Company had recorded accounts payable and accrued
expenses (including interest) and other liabilities of $3.2 million. Due to the
sale of Lajitas, the Company has sufficient funds to pay its current general and
administrative operating expenses; however, the Company is unable to repay its
notes payable at the face amounts and the related accrued interest.

<PAGE>

     In assessing the Company's liquidity, the impact of income taxes has been
considered. The Company does not expect its cash flow to be affected by income
taxes in the foreseeable future because of its net operating loss carry forward.

     The impact of inflation on the Company over the past several years has not
been material.

     No major additions to property, plant and equipment are currently
anticipated.

ITEM 3. CONTROLS AND PROCEDURES.

Evaluation of Disclosure Controls and Procedures

     Based on their evaluation as of a date within 90 days of the filing date of
this Quarterly Report of the Company on Form 10-QSB for the period ended March
31, 2003, the Company's Chief Executive Officer, its President and Principal
Executive Officer and its Senior Vice President - Finance and Principal
Financial and Accounting Officer have concluded that the Company's disclosure
controls and procedures (as defined in Rules 13a-14(c) and 15d-14(c) under the
Securities Exchange Act of 1934) are effective to ensure that information
required to be disclosed by the Company in reports that it files or submits
under the Securities Exchange Act of 1934 is recorded, processed, summarized and
reported within the time periods specified in Securities and Exchange Commission
rules and forms.

Changes in Internal Controls

     There were no significant changes in the Company's internal controls or in
other factors that could significantly affect these controls subsequent to the
date of their evaluation, including any corrective actions with regard to
significant deficiencies and material weaknesses.

                           PART II - OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS

None

ITEM 2. CHANGES IN SECURITIES

None

ITEM 3. DEFAULT UPON SENIOR SECURITIES

None

<PAGE>

ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

None

ITEM 5. OTHER INFORMATION

     Pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of
the Sarbanes-Oxley Act of 2002, each of the Chief Executive Officer and the
Senior Vice President - Finance and Principal Financial and Accounting Officer
of the Company has certified that the Quarterly Report of the Company on Form
10-QSB for the period ended March 31, 2003 (this "Report") fully complies with
the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of
1934 and that the information contained in this Report fairly presents, in all
material respects, the financial condition and results of operations of the
Company.

ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K

A. Exhibits Required by Item 601 of Regulation S-B.

                                                            *Filed Herein or
                                                       Incorporated by Reference
                       Exhibit                             from Exhibit

3        (a) Certificate of Incorporation, as          3(a) 1989 Form 10-K
             Amended, through June 6, 1989
         (b) Articles of Amendment to Certificate      3(b) 1989 Form 10-K
             of Incorporation dated June 7, 1989
         (c) Articles of Amendment to Certificate      3(c) 1993 Form 10-K
             of Incorporation dated May 21, 1993
         (d) Bylaws, as Amended, through date          3(d) June 30, 1989 Form
             10-K hereof

99.1         Certifications Furnished Pursuant to 18 U.S.C.    *
             Section 1350, As Adopted Pursuant to Section
             906 of the Sarbanes-Oxley Act of 2002

B. Reports on Form 8-K.

   None

<PAGE>

                                   SIGNATURES

     In accordance with the requirements of the Securities Exchange Act of 1934,
the registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.

                                      SOUTHERN INVESTORS SERVICE COMPANY, INC.


                                       /s/ Walter M. Mischer, Jr.
                                      ------------------------------------
                                      WALTER M. MISCHER, JR.
                                      President - Principal Executive Officer


                                       /s/ Eric Schumann
                                      ------------------------------------
                                      ERIC SCHUMANN
                                      Senior Vice President - Finance
                                      Principal Financial and Accounting Officer


                                      DATE: May 14, 2003

<PAGE>

                                 CERTIFICATIONS

I, Walter M. Mischer, Sr., certify that:

1.   I have reviewed this quarterly report on Form 10-QSB of Southern Investors
     Service Company, Inc.;

2.   Based on my knowledge, this quarterly report does not contain any untrue
     statement of a material fact or omit to state a material fact necessary to
     make the statements made, in light of the circumstances under which such
     statements were made, not misleading with respect to the period covered by
     this quarterly report;

3.   Based on my knowledge, the financial statements, and other financial
     information included in this quarterly report, fairly present in all
     material respects the financial condition, results of operations and cash
     flows of the registrant as of, and for, the periods presented in this
     quarterly report;

4.   The registrant's other certifying officers and I are responsible for
     establishing and maintaining disclosure controls and procedures (as defined
     in Exchange Act Rules 13a-14 and 15d-14) for the registrant and we have:

     (a) designed such disclosure controls and procedures to ensure that
         material information relating to the registrant, including its
         consolidated subsidiaries, is made known to us by others within those
         entities, particularly during the period in which this quarterly report
         is being prepared;

     (b) evaluated the effectiveness of the registrant's disclosure controls and
         procedures as of a date within 90 days prior to the filing date of this
         quarterly report (the "Evaluation Date"); and

     (c) presented in this quarterly report our conclusions about the
         effectiveness of the disclosure controls and procedures based on our
         evaluation as of the Evaluation Date;

5.   The registrant's other certifying officers and I have disclosed, based on
     our most recent evaluation, to the registrant's auditors and the audit
     committee of registrant's board of directors (or persons performing the
     equivalent functions):

     (a) all significant deficiencies in the design or operation of internal
         controls which could adversely affect the registrant's ability to
         record, process, summarize and report financial data and have
         identified for the registrant's auditors any material weaknesses in
         internal controls; and

     (b) any fraud, whether or not material, that involves management or other
         employees who have a significant role in the registrant's internal
         controls; and

6.   The registrant's other certifying officers and I have indicated in this
     quarterly report whether or not there were significant changes in internal
     controls or in other factors that could significantly affect internal
     controls subsequent to the date of our most recent evaluation, including
     any corrective actions with regard to significant deficiencies and material
     weaknesses.

     Date: May 14, 2003              /s/  Walter M. Mischer, Sr.
                                     -------------------------------------------

                                          Name:  Walter M. Mischer, Sr.
                                          Title: Chief Executive Officer

<PAGE>

I, Walter M. Mischer, Jr., certify that:

1.   I have reviewed this quarterly report on Form 10-QSB of Southern Investors
     Service Company, Inc.;

2.   Based on my knowledge, this quarterly report does not contain any untrue
     statement of a material fact or omit to state a material fact necessary to
     make the statements made, in light of the circumstances under which such
     statements were made, not misleading with respect to the period covered by
     this quarterly report;

3.   Based on my knowledge, the financial statements, and other financial
     information included in this quarterly report, fairly present in all
     material respects the financial condition, results of operations and cash
     flows of the registrant as of, and for, the periods presented in this
     quarterly report;

4.   The registrant's other certifying officers and I are responsible for
     establishing and maintaining disclosure controls and procedures (as defined
     in Exchange Act Rules 13a-14 and 15d-14) for the registrant and we have:

     (a) designed such disclosure controls and procedures to ensure that
         material information relating to the registrant, including its
         consolidated subsidiaries, is made known to us by others within those
         entities, particularly during the period in which this quarterly report
         is being prepared;

     (b) evaluated the effectiveness of the registrant's disclosure controls and
         procedures as of a date within 90 days prior to the filing date of this
         quarterly report (the " Evaluation Date"); and

     (c) presented in this quarterly report our conclusions about the
         effectiveness of the disclosure controls and procedures based on our
         evaluation as of the Evaluation Date;

5.   The registrant's other certifying officers and I have disclosed, based on
     our most recent evaluation, to the registrant's auditors and the audit
     committee of registrant's board of directors (or persons performing the
     equivalent functions):

     (a) all significant deficiencies in the design or operation of internal
         controls which could adversely affect the registrant's ability to
         record, process, summarize and report financial data and have
         identified for the registrant's auditors any material weaknesses in
         internal controls; and

     (b) any fraud, whether or not material, that involves management or other
         employees who have a significant role in the registrant's internal
         controls; and

6.   The registrant's other certifying officers and I have indicated in this
     quarterly report whether or not there were significant changes in internal
     controls or in other factors that could significantly affect internal
     controls subsequent to the date of our most recent evaluation, including
     any corrective actions with regard to significant deficiencies and material
     weaknesses.

     Date: May 14, 2003      /s/  Walter M. Mischer, Jr.
                             ---------------------------------------------------

                                  Name:  Walter M. Mischer, Jr.
                                  Title: President - Principal Executive Officer

<PAGE>

I, Eric Schumann, certify that:

1.   I have reviewed this quarterly report on Form 10-QSB of Southern Investors
     Service Company, Inc.;

2.   Based on my knowledge, this quarterly report does not contain any untrue
     statement of a material fact or omit to state a material fact necessary to
     make the statements made, in light of the circumstances under which such
     statements were made, not misleading with respect to the period covered by
     this quarterly report;

3.   Based on my knowledge, the financial statements, and other financial
     information included in this quarterly report, fairly present in all
     material respects the financial condition, results of operations and cash
     flows of the registrant as of, and for, the periods presented in this
     quarterly report;

4.   The registrant's other certifying officers and I are responsible for
     establishing and maintaining disclosure controls and procedures (as defined
     in Exchange Act Rules 13a-14 and 15d-14) for the registrant and we have:

     (a) designed such disclosure controls and procedures to ensure that
         material information relating to the registrant, including its
         consolidated subsidiaries, is made known to us by others within those
         entities, particularly during the period in which this quarterly report
         is being prepared;

     (b) evaluated the effectiveness of the registrant's disclosure controls and
         procedures as of a date within 90 days prior to the filing date of this
         quarterly report (the " Evaluation Date"); and

     (c) presented in this quarterly report our conclusions about the
         effectiveness of the disclosure controls and procedures based on our
         evaluation as of the Evaluation Date;

5.   The registrant's other certifying officers and I have disclosed, based on
     our most recent evaluation, to the registrant's auditors and the audit
     committee of registrant's board of directors (or persons performing the
     equivalent functions):

     (a) all significant deficiencies in the design or operation of internal
         controls which could adversely affect the registrant's ability to
         record, process, summarize and report financial data and have
         identified for the registrant's auditors any material weaknesses in
         internal controls; and

     (b) any fraud, whether or not material, that involves management or other
         employees who have a significant role in the registrant's internal
         controls; and

6.   The registrant's other certifying officers and I have indicated in this
     quarterly report whether or not there were significant changes in internal
     controls or in other factors that could significantly affect internal
     controls subsequent to the date of our most recent evaluation, including
     any corrective actions with regard to significant deficiencies and material
     weaknesses.

     Date: May 14, 2003         /s/  Eric Schumann
                                ----------------------------------------------

                                     Name: Eric Schumann
                                     Title:   Senior Vice President - Finance
                                     Principal Financial and Accounting Officer